Category Archives: Graph

Log Graphs 1


Car: 2009 Impreza 2.0 Turbo Diesel, 110 kW / 148 hp / 150 PS, European domestic market, Euro 4 spec.

Important: Newer Boxer Diesel generations (Euro 5/6) may show different behaviour!

ECU firmware: patched ROM for unlimited logging, otherwise stock.
Protocol: SSM2 via CAN
More than 120 items had been logged, plenty of RAM variables (*) plus standard SSM2 items at roughly 170 ms interval.


I prepared two graph images plotting some interesting parameters, click picture for full resolution:

Image 1/2


Image 2/2


Additional details

… at specific time positions:

#1: State before active regeneration

Time @ ~ 33 ½ min
Cruise Control: active
Vehicle Speed*: 110 km/h
Engine Speed: 2300 rpm
Gear: 5
Coolant Temperature: 93 °C
Injections: 2 (pre + main)
Soot Accumulation Ratio: 64 %
DPF Pressure Difference: ~ 5 kPa
Exhaust Gas Temperature (EGT) Catalyst Inlet: 345 °C
EGT DPF Inlet: 370 °C
Intake Air Amount: 430 mg/cyl
Mass Air Flow: 33.8 g/s
Manifold Absolute Pressure (MAP)*: 126 kPa
Inlet Air Temperature: 25 °C
Manifold Air Temperature: 48 °C
Fuel Temperature: 58 °C
Throttle Opening Angle: 79 deg
EGR Valve Opening Angle: 38 deg
Final Oil Dilution Rate*: -1.9 mg/s (evaporation)
Oil Dilution Amount: 282.0 g (4.6 %)

#2: Soot 65%, preparing for DPF regeneration

@ 33 ¾ min
Soot Accumulation Ratio* reaches 65%, this triggers active regeneration preparations. Note: I am referring to the actual RAM value, diagnostic parameter may indicate 65% earlier due to rounding.
Apparently ECU now does 3 injections (pre + main + after) when power demand is high enough, no post injections yet

#3: Active Regen ON

@ 34:04; = 20 seconds after #2, DPF Regeneration Switch turns ON
EGR valve closes instantly, 0 deg
Manifold Air Temperature dropping
Boost Control opens VGT immediately, from 52 to 25%
Manifold Absolute Pressure* dropping
pilot-injection kicks in, 2 injections (pilot C + main)
post-injections begin to fade in but not active yet

#4: Post-Injections

@ 33 seconds after #2, post-injections A + B become operational (injection amount > 0)
oil dilution rising
EGTs climbing
Manifold Absolute Pressure*: 75 kPa (~ 25 below ambient), varying, stays below ambient most of the time during regen at low power demand
EGT Catalyst Inlet: 340 °C
EGT DPF Inlet: 320 °C
injections: 4 (pilot C + main + post A + post B)

#5: Coasting Fuel Cut-Off During Regen

Example @ 35:12
EGR valve opens instantaneously, 70 deg; EGR behaves rather digitally during regen – either fully closed (0 deg, for max EGT) or max opened (70 deg, less fresh air)
Throttle Opening Angle: rising up to 31 deg
injections: 0
Fuel Consumption*: 0 mm³/s
oil dilution going down slowly due to estimated evaporation
EGT Catalyst Inlet: decreases fast, EGT at DPF inlet (> 600 °C) follows with a delay
Engine Speed: gear change from 5th to 6th to reduce engine braking effect

#6: Idling with Active Regen ON

@ 45:30
Engine Speed: 800 rpm
Post A Injection Amount*: 0
Post B Injection Amount*: ~ 8 mm³/st
Apparently while idling the ECU prefers the 2nd post-injection (“B”), otherwise during driving it’s rather mixed
Final Oil Dilution Rate: ~ 20 mg/s (medium)
Boost Control: 25 % (VGT fully open)
Manifold Absolute Pressure*: 74 kPa
Throttle Opening Angle: 5.5 deg
EGR Valve Opening Angle: 0 deg
Intake Air Amount: 370 mg/cyl
Mass Air Flow: 9.8 g/s

#7: DPF Regeneration OFF

@ 46:15, decision is based on elapsed time from #2, achieved soot level does not matter (!)
DPF Regeneration SW had been ON for 12.2 minutes
all post-injections off
Oil Dilution Amount*: 299.6 g (4.9 %) = + 0.3 % during regeneration
EGR back to normal operation
Boost Control: 65 % instantly (max speed, spooling up turbo)
MAP rising
EGT Catalyst Inlet: 270 °C
EGT DPF Inlet: 490 °C

Yet another color map for EcuFlash

Perhaps another color map for EcuFlash might be interesting? I wrote a little SageMath python script to generate a ScoobyRom-like color map file.

EcuFlash using ScoobyRom color map

EcuFlash using ScoobyRom color map

Note: Although generated color map matches ScoobyRom’s precisely, EcuFlash applies colors based on “min” and “max” specified in XML definitions.

Excerpt from EcuFlash definition file: 32BITDIESELBASE.xml

<scaling name="ChargeAirPressure" units="kPa" toexpr="x" frexpr="x" format="%.0f" min="0" max="255" inc="1" storagetype="uint8" endian="big"/>

Whereas ScoobyRom scales colors ranging from a map’s actually used mininum and maximum. For example, if you would change min="0" to min="100" in above scaling definition, low value colors would appear bluish like in ScoobyRom, effectively making map graphics cover more/most of available color range.


1) Download file scoobyrom-map.odt

2) Rename downloaded file to, since normal file extension is not allowed on

3) Move file into EcuFlash’s color maps folder, i.e.

C:\Program Files (x86)\OpenECU\EcuFlash\colormaps\

4) Launch or restart EcuFlash.

5) Via EcuFlash menu: File → Options → Appearance → Default Color Map
Select “”
(Btw., default color map directory can also be defined in Options)

Color Map File Format

Color map format is plain text ASCII file, usually 256 lines as in this case, specifying RGB values which will be applied to maps, from low to high:

153 153 255
153 154 255
153 156 255
152 157 255
255 110 103
255 107 102
255 105 102
255 102 102

ScoobyRom v0.8.2 Released

What’s new in v0.8.2:
  • Export as TunerPro XDF format.
  • Support for ROM type SH72531 (1.25 MiB = 1280 KiB size)
  • Display Reflash Count if known/available (Properties-window).

Project homepage: ScoobyRom Software


Already implemented in previous version is the ability to parse and display ROM Date (year-month-day), diesel as well as petrol type encodings. May not work for all ROM types (yet), though. AFAIK, ScoobyRom is the only software parsing this Denso specific date.

ScoobyRom 0.8.2 - Properties window, CID JZ4A211B

ScoobyRom 0.8.2 – Properties window, CID JZ4A211B

TunerPro (XDF)

Due to my intense work on BMW ECUs in recent years, I got familiar with TunerPro which is a generic ROM editor. It is quite popular in the BMW community, it can handle lots of data format options. Its definition format “XDF” is XML-based as usual. As an exercise to verify XDF knowledge I implemented XDF output in ScoobyRom.

Compared to RomRaider, reading an XDF containing hundreds of tables is very fast, almost instant. TunerPro is Windows-only and closed-source however.

TunerPro 5.00.8853 screenshot, Windows 10 x64, XDF generated by ScoobyRom

TunerPro 5.00.8853 screenshot, Windows 10 x64, XDF generated by ScoobyRom

ScoobyRom v0.8.0 Released

New in v0.8.0:
  • Navigation bar visualisation.
  • Additional columns (conversion: Multiplier & Offset or NaN if not used; Axes locations: XPos, YPos)
  • Select all/none
  • RomRaider definitions export: choose whether to export all/selected/annotated tables.
  • Roughly 3 times faster when scanning whole ROM.
  • Lots of misc improvements in code at least…

Go to homepage: ScoobyRom Software
Post software specific feedback there, please!
Also, if you find this software useful consider to “like” above page as minimum feedback and motivation for future work!

ScoobyRom v0.7.1 Released

New in v0.7.1:
  • Dynamically adjust icon size (Ctrl-+, Ctrl--, Ctrl-0)
  • Edit -> Copy Table: Can paste values into existing RomRaider table, spreadsheet (LibreOffice Calc, Microsoft Excel), text editor etc.
  • Miscellaneous improvements as always.
  • Also tested on Windows 10, no changes were necessary.

Go to page: ScoobyRom Software
Enjoy and provide software specific feedback there, please!

ScoobyRom v0.7.0 Released

Go to page: ScoobyRom Software

Enjoy and provide software specific feedback there, please!

Oil Dilution Graph

Shown graph contains a complete DPF active regeneration process – the rising section (750 seconds duration = 12.5 minutes).
Basically, oil dilution is driven by:

  1. post-injections during active DPF regeneration
  2. estimated diesel fuel evaporation

According to internal algorithm and logged data, normal operation does not increase dilution. Oil dilution slowly decreases as the ECU estimates fuel evaporation out of engine oil. (On Euro 4 at least, this algorithm is also running if ignition is on, engine not running but coolant temperature warm enough).
Active regeneration however uses one or more post-injections (small additional late injections – during exhaust stroke) in order to heat up the DPF, raising oil dilution amount, at much higher rate therefore winning over evaporation.
Notice these short intermittent steps during regeneration – these are caused by coasting – ECU suspending all injections, including post-injections.
Wouldn’t coasting cool down the DPF then by pushing rather cold air through the system? To mitigate this, the software fully opens EGR valve (70 deg). As soon as injections resume, EGR valve is being closed again. Normally, during active regeneneration it is in fully closed position (0 deg) helping to increase exhaust temperature (more oxygen).
If you look carefully, you can spot more evaporation going on after regeneration had finished compared to before it started. This is mainly due to higher engine temperature, having reached normal operating conditions of around 90 °C. For evaporation to get going it needs temperatures beyond 30 °C, the higher the better.
Also take a look at post “Estimated Distance to Oil Change” for additional information.